Monday 26 November 2001 05.33 EST
First published on Monday 26 November 2001 05.33 EST

When, less than two years ago, Jack Straw introduced the bill which became the Terrorism Act 2000, he proclaimed: "We will have handed the terrorists the victory that they seek if, in combating their threats and violence, we descend to their level and undermine the essential freedoms and rule of law that are the bedrock of our democracy."

He is now one of the signatories to the emergency anti-terrorism bill which does precisely that. The bill goes before the Commons again today. In its first serious test, the human rights convention is sidelined.

Bombings, killings and maimings in the name of some maniacal political or religious cause are unspeakable acts. Juries readily convict and judges sentence harshly. The Terrorism Act 2000 extended the powers of the police to investigate, arrest and detain.

It created new offences, which permit the courts of this country to deal with terrorist acts and their planning, wherever in the world those acts are carried out. All that is required is a charge, and evidence, leading to proof.

There are, in place, provisions which enable a court to sit in camera, and to take evidence from officers of the security services in the presence of the accused and his advisers, but behind screens. I have prosecuted men accused of letter-bombing in such circumstances.

But ministers think these recent safeguards are not enough: in the aftermath of September 11, a gesture has to be made. Their attitude is that proof of a criminal charge is a redundant complication: those of us who cling to the desirability of such a technicality are "airy-fairy liberals".

After all, the new bill is not aimed at the Brits: it sweeps up only foreign nationals who are here on sufferance. Part 4 of the anti-terrorism bill is about indefinite detention without charge or trial. Under its provisions, the home secretary will act merely on suspicion and belief. His function is to evaluate the risk presented to national security on the information that is put before him, not to come to any final conclusion that he is in fact a terrorist.

The quality of that information cannot be challenged or tested by the alleged terrorist because he will not be told what it is. No doubt the prime suppliers of such secret information will be the intelligence services of this and other countries. Their informants and their motivation will remain unknown - even to the minister.

Concurrently, the powers of the intelligence services are extended by the bill. For the first time, secret investigators, unaccountable to any police authority, may pry into any one of the 32m tax and VAT files kept on individuals in this country. Further, the Ministry of Defence police are given an entirely novel jurisdiction to exercise powers under the Terrorism Act 2000, and to act as constables not just on Ministry of Defence property, but anywhere in the country.

But, says Mr Blunkett, do not fear: there is a right of appeal to the special immigration appeals commission, a high court judge, an immigration judge and a lay person with experience in security matters. Somebody in the Home Office had a bright idea. The commission was originally set up to review the decisions of the home secretary to deport individuals, not to lock them up indefinitely. But it is conveniently in place for the government's present purposes.

It has special procedures. The commission can receive evidence which would not be admissible in a court of law. The appellant, and his ordinary legal representative, will be excluded from the closed sessions. He will be represented by a security-cleared, special advocate, appointed by the commission: but the special advocate may not, without leave, take instructions from the appellant on the evidence and submissions to be heard by the commission in secret.

Furthermore, the commission's reasons for their decision will be circumscribed by their duty not to disclose the secret information upon which it is based. The basic principles of natural justice are violated. I cannot contemplate how the special advocate could possibly challenge effectively the case for the Home Office, based on hearsay and unattributable assertion, without any instructions from the appellant himself.

The commission's lack of effectiveness as a safeguard against arbitrary decisions was exposed in a judgment of the judicial committee of the House of Lords last month. The commission had been bold enough to disagree with the home secretary's decision to deport a certain Mr Rehman in December 1998.

On October 21, the judicial committee, composed of the most liberal of the lords of appeal, put the commission firmly in its place. It was reminded that an appellate body has a limited function: it traditionally allows a considerable margin to the minister who makes the decision. "Even if the appellate body prefers a different view," said Lord Hoffmann, "it should not ordinarily interfere with a case in which it considers that the view of the home secretary is one which could reasonably be entertained."

The bill seeks to exclude any other form of challenge to the home secretary's decision, whether by way of application for a writ of habeas corpus or judicial review. Habeas corpus is the prerogative writ familiar to the common law at least as long ago as the 13th century, challenging arbitrary detention, by forcing the authorities to justify their actions.

Judicial review is a flexible remedy whereby the high court exercises its supervisory powers over the decisions of officials. Both remedies are inimical to secrecy and are of high constitutional importance.

When I questioned the Home Office minister, Lord Rooker, on October 15 on the floor of the House of Lords about the proposed abolition of habeas corpus for this bill, his reply was that the government was "seeking to streamline the position".

He added: "I do not want to fall out with the legal nobles here. I assure the noble lord that the legal industry, or legal trade, in this country will still be able to earn a living. We are not going to put them out of business, but neither are we going to let them misuse the legal process on key decisions to frustrate what we are seeking to do with our partners, as has happened in the past."

Well that's all right then. Perhaps the noble lord, and the Home Office, might recall with some humility the 38th article of Magna Carta, 1215: "In future no official shall place a man on trial upon his own unsupported statement, with out producing credible witnesses to the truth of it."

The truth is that detention without trial does not stop terrorism: its potential for injustice breeds it. It was introduced in 1971 in Northern Ireland in a moment of panicky response to the growing terrorism of the time.

Four years later, its dangers were revealed and the practice ceased. Jack Straw had it right: the essential freedoms of the state must be steadily upheld in the face of terrorist threat. The rule of law must not, in sudden alarm, be undermined.

Lord Thomas of Gresford QC is a home affairs spokesman for the Liberal Democrats and has both prosecuted and defended in terrorist trials.